The present invention relates to a self-sampling device which permits the obtainment of samples from body cavities and a method for using the device. In particular, the present invention permits women to self-sample to obtain cervical cells for testing for Human Papillomavirus DNA.
Cytologic screening programs have been associated with dramatic reductions in the incidence of cervical cancer in certain parts of the world. Cytologic screening typically involves obtaining a sample of cells or tissue from the cervix and testing the sample for the presence of cervical carcinoma cells. The most common method used for this testing is the Papanicolaou (Pap) smear. Pap smears are generally performed by a physician during gynecological examination of the patient using sampling apparatus designed for use only by a physician. Due to the inconvenience, time and discomfort involved in having the Pap smear test performed by a physician, many women do not have the test performed at the recommended intervals. Also, in many countries, women do not have sufficient access to health care providers or health care facilities to have regular Pap smear testing performed. As a result, in these countries, cytologic screening to reduce the incidence of cervical cancer has not been successfully implemented.
Recent studies have shown that testing of samples of cervical cells for human papillomavirus (HPV) DNA can be used to screen for cervical disease. It has been reported that HPV DNA testing of clinician-obtained cervical samples has a sensitivity for detection of high-grade cervical squamous intraepithelial lesions and invasive cervical cancer that is equivalent or superior to that of a Pap smear. (Wright et al. 2000, HPV DNA testing of self-collected vaginal samples compared with cytologic screening to detect cervical cancer, Jour. Am. Med. Assoc. Vol. 283, No. 1). Clinician-obtained samples for HPV DNA testing have many of the same drawbacks as Pap smears, however, because the samples must be obtained by health care professionals and therefore are inconvenient, time consuming, uncomfortable, and may not be available to women in certain parts of the world.
Wright et al. have reported the results of studies showing that self-collected cervical cell samples can be used effectively for HPV DNA testing as a means of screening for women at high risk of having cervical disease. This screening can be used to identify women who should have more extensive testing performed. Accordingly, HPV DNA testing of self-collected samples can be used to identify women at high risk of having cervical disease in parts of the world where access to physicians or health care facilities is limited. Therefore, there is a need for a relatively easy and inexpensive means for self-collecting of samples to test for HPV DNA.
Prior devices used for collecting samples of cervical cells have several drawbacks and disadvantages. For example, many devices require a physician to collect the sample. Kist, U.S. Pat. No. 4,700,713, describes a sampling device comprised of bristles shaped to fit the cervix mounted on a handle, with each bristle having at least one longitudinal sharp edge. This device is intended for sampling only by a physician. Proper placement of the shaped bristles of the device with respect to the cervix must be effected by a physician during a gynecological examination and there is no means provided to guide the sampling device and assure proper placement to permit self-sampling.
White, U.S. Pat. No. 4,175,008, describes a culture specimen collection and transport device. The culture specimen collection portion of the device consists of a swab with an absorbent material at the end of the swab. There is no structure associated with the swab that would permit self-sampling of cervical tissue. Indeed, White states that his device is intended for use by physicians to obtain culture specimens, particularly of the ears, nose and throat. Accordingly, such a device could not be used for self-sampling.
Although several devices for self-sampling of the cervix have been developed, each of the devices has drawbacks and disadvantages. Canna, U.S. Pat. No. 5,121,752, describes a device for self-sampling to obtain PAP smear samples. A sample is obtained using a scraper head on a handle to scrape a sample from the cervix. A shaped speculum is used to insert the sampling device. In use, a hand mirror is required to locate the device properly to obtain a sample. This makes the device relatively difficult to use to obtain a sample. Also, the scraping action of the sampling portion of the device can cause discomfort, discouraging use of the device.
Other devices for self-sampling use absorbent swabs or other methods to collect the samples. For example Sak, U.S. Pat. No. 5,787,891, and Worthen, U.S. Pat. No. 5,445,164, describe self-sampling devices that use absorbent materials at the end of plunger type devices to absorb samples from the area of the cervix. These devices are relatively complicated in their design, rendering them more difficult to use and more expensive to manufacture. Also, relatively precise placement of the device is necessary to ensure a representative sample is obtained. The need for precise placement of self-sampling devices is a disadvantage, as it is difficult for a woman to ensure precise placement during self-sampling. In addition, absorbent material will take longer to release its captured specimen, and may not release all that it has absorbed. This can reduce the dependability of the test if the cells that are the subject of the test are more readily absorbed by the absorbent material.
Accordingly, the present invention overcomes one or more of the drawbacks or disadvantages of the prior art and provides an easy to use and inexpensive device to permit self-sampling of a body cavity, and in particular to permit self-sampling of the cervix to obtain a sample for testing for HPV DNA.
The present invention provides a device for self-sampling to obtain a sample of cells from the cervix to be tested for HPV DNA. In one embodiment, the device is comprised of a mop-like brush made of a plurality of elongated flexible bristles which are attached to a handle. The brush and handle are placed within an annular insertion shield. The distal end of the insertion shield is designed to assist in insertion of the sampling device into the vaginal cavity and in positioning the sampling device in the area of the cervix to obtain a sample of cervical cells.
After the sampling device is fully inserted within the vaginal cavity and the distal end of the insertion shield is located proximate to the cervix, the insertion shield is at least partially withdrawn, exposing the mop-like brush of the device to the cervix. The exposed mop-like brush is then rotated by the handle to obtain a sample of cells from the epithelium layer of the cervix adhering to the mop-like bristles of the brush. Due to the design of the mop-like brush, a representative sample of cells can be obtained without the need to locate the sampling device in an exact location relative to the cervix. After the sample has been collected, the handle is used to pull the mop-like portion back into the insertion shield and the sampling device is removed from the vagina. The mop-like brush containing the cell sample can then be tested to determine the presence of HPV DNA.
Among the advantages of the device is that a sample of cervical cells can be easily obtained by women without the intervention of a physician or health care professional. Accordingly, the time and expense involved in obtaining a sample is reduced. A further advantage of the invention is that the mop-like brush allows a representative sample of the cervix area to be obtained on the bristles of the mop-like brush without the need to locate the device precisely in relation to the cervix. Also, tests performed on samples obtained using non-absorbent material are more consistent than samples obtained on absorbent material. Accordingly, the sampling device is easy to use to obtain relatively accurate test results for HPV DNA.